yes you can, but I only prune mine when some of the stems are growing across the windows. They need very little pruning, just to keep it in the confines of the space you have.

I prune mine march/april time.

and welcome to GoY.

check out my site for proper pruning techniques.. www.atlanta-area-tree-service.com

ya know id say a lot of plants or trees are trainable . im training a cherry tree into an arch and a willow down the river twisted with another willow for when i kick the bucket . you can see them on my blogs . most things id say are potentialy just not typicaly trained . i mean realy theres not many plants that can climb up a wall without any help realy . ivy isone that can . id guess being flexible and woody being the importent things realy . sorry i just like being different if it didnt show lol .